WASHINGTON D.C. – Four different people came out to the mound to discuss things with John Maine. Ramon Castro went over. Julio Franco joined in. Rick Peterson and David Wright made the trip.

Maine had been looking as if he might pitch into the ninth inning yesterday, but in the seventh, he got in a jam. Owning a one-run lead over the Nationals, he opened the inning by allowing a leadoff double and a walk, prompting the conference.

Maine, however, got through it. He retired the next three Nationals to hold the Mets’ edge, getting Jesus Flores on a force play and striking out Chris Snelling and Robert Fick, the latter on a 93-mph, full-count whiff.

In the Mets’ 1-0 win over the Nationals yesterday, Maine was magnificent again. He fired seven shutout innings at RFK Stadium, giving up only three hits and notching a career-best eight strikeouts.

Maine’s 4-0 this year and his ERA – 1.35 – ranked yesterday as the second best in the National League behind the Braves’ Tim Hudson.

“It is,” Billy Wagner said, when told that Maine’s month has been so marvelous. “But after what we saw in the playoffs and his demeanor, I guess a lot of us aren’t that shocked.”

Nevertheless, Maine’s season has been surprising. He was a good pitcher for the Mets last year and his postseason outings were impressive. This season, though, Maine has been exceptional. He’s given up 18 hits in 33.1 innings – a fantastic ratio – and the Mets are 5-0 in games he starts.

“I’m pleased,” Maine said of his strong April. “I’ve still got a lot of stuff to work on. I’ve got five more months. I’ve just got to keep it going. The month’s over, and I’ve just got to worry about May now.”

The Mets, however, continued to slump at the plate yesterday, as they scored one run and tallied three hits. The run came when Carlos Beltran smacked a one-out homer to right in the sixth inning off righty Jason Bergmann. Though they took 2 of 3 this weekend, the Mets didn’t impress at the plate. They only put up 10 runs in 30 innings.

As for Maine, he gave up only one hit in the first five innings and now has pitched at least seven innings in his last three games and in four of his five this year.

After he gave up Austin Kearns’ leadoff double and Ryan Church’s walk in the seventh, he was aided by a good defensive play by Franco at first base. Flores tried to bunt both runners over, but Franco – who said he was “cheating big time” – threw Kearns out at third. Maine then added his two strikeouts.

“If [Maine] keeps going, I think he’s going to be up there soon,” Willie Randolph said, referring to being mentioned with the top pitchers. “He’s got a long way to go, but I like what I’m seeing right now.”

In the eighth, the Mets worked out of another jam when Aaron Heilman continued to pitch poorly. Heilman loaded the bases on two singles and a walk, but with two outs, Scott Schoeneweis came in and got Church on an inning-ending grounder to first.